Selections

Introduction

Hexagon software's modeling tools vary according to the type of object selected.
Certain tools work with edges and not faces, where other tools adapt their behavior to
the chosen selection mode. Therefore, it is important to choose the right selection mode
before you choose a tool.

General

The complete selection palette.

Types of Selections

There are four types of selections:

Vertices (or points): the basis of all 3D construction.

Edges: made up of at least 2 points.

Faces: made up of at least 3 edges, with no maximum.

Object: several faces making up a surface, or segments making up a line.

Selection modes, as the name implies, select only certain elements:

In select point mode, you can affect only points.

In select edge mode, you can affect only an edge (and the two points that make it up).

In select face mode, you can affect only a face (including the edges and points that make it up).

In select object mode, you affect the whole object.

The same tool, move or translate for example, can have very different results,
depending on whether you want to retouch a detail (move a point on the object) or make
a bigger change such as an assemblage (moving the whole object in the scene).

To change from one mode to another, just click on the icon for the mode you
want in the selection palette at the top of the screen between the manipulators palette
and the modeling tools palette.

Select Auto

Select auto is a fifth mode that lets you work in all the modes without having to
use the keyboard shortcuts or clicking on the other mode's icons. The first item selected
on the object becomes the selection mode by default (facets, for example), until you
deselect everything. A single click in the 3D workspace (next to your object, for
example) turns the mode back to select auto. A double-click in the 3D workspace changes the
mode to select object.

You can also double-click on another object, thereby passing on select auto
mode for that object

Soft Selection

Soft selection in action.

Complementing the selection modes, there is a specific option that
smoothly increases the influence of a manipulation around the active selection: the “Soft
Selection”.

For example, on a face, select a polygon corresponding to a part of the cheek.
With no soft selection, if you move the selected polygon, it will be the only element
moving. Activate the smooth selection, and an influence area will appear around the
selected element, represented by red points (maximum influence) whose color becomes
black (minimum influence). Move it now, you will see that a part of the nose is modified
as well, smoothly following your manipulation.

Two parameters and one option, in the tool properties panel, will allow you to
fine-tune this soft selection:

Radius: defines the size of the influenced area around the selection.

Softness: the influence ratio in the soft selection area. The higher the value, the less flexible the modified surface.

Freeze: Allows you to keep the same influence area around the selection after the modification.

Note: The soft selection only works with the 3D Manipulator (Move, Rotate, Scale,
Universal) and within the tweak tool.

Keyboard shortcut: Ctrl+Shift+mouse click&drag to change the radius.

Selection Memorization

Note that the active selection is memorized if you leave one mode for another
(unless you are in auto select mode). For example, while working in select point mode
you have five points selected, and you change to select face mode. Hexagon hides the
selected points while you work with the faces, until you reselect the select point mode.
Hexagon then hides the faces you selected until you again return to select face mode.

It is not possible to work in several modes at once, such as with faces and
points.

Selection Methods

The following modes can create selections in different ways: they work with
points, edges and faces selection tools.

Paint

The paint mode lets you draw a selection by clicking and dragging the cursor over the
form, like a brush on an object, leaving behind it the selected elements. Any click on the
object outside the selection deselects the existing selection and starts a new one.

The default mode for the left click of the mouse is available in the selection
menu.

Drag

The drag mode lets you move the selection according to the last movement made by
the manipulator, without even clicking on it. Hexagon software keeps in memory the
last operation and applies it to the new element when you click and drag. This is very
practical for making fast changes and fine tuning.

When dragging over unselected items, it selects these items like it does in paint
mode.

Alternative mode for the mouse left click, which can be used by clicking the
Drag icon in the selection palette.

Rectangle Lasso

The rectangle lasso mode lets you make a selection with a rectangular lasso. Frame the elements
to select with a click and drag of the mouse. When the mouse button is released,
all the items within the rectangle are selected.

The default mode for the right click of the mouse is available in the selection menu.

When using the rectangular lasso, the Shift key adds, and the Ctrl key submenu.
tracts from the selection.

However, you must first launch the rectangle lasso tool before pressing the
modifier key (Ctrl or Shift).

Polygon Lasso

The polygon lasso mode lets you make a selection with a polygon drawn around the elements
in a series of clicks. Finish your lasso selection by hitting the Enter key, or click on the
Validate button in the tool properties palette.

The alternative mode for the right click of the mouse is available by clicking on
the button drag lasso icon in the selection menu.

When using the polygon lasso, the Shift key adds and the Ctrl key subtracts
from the selection.

However, you must first launch the polygon lasso tool before pressing the modifier key (Ctrl or Shift).

Selection Operations

Hexagon has basic operations like adding or subtracting an element from the
selection.

These operations are accessed with the Shift key, which switches back and forth
depending on the selection:

Shift + Click a selected item to deselect it.

Shift + Click a non selected item to add it to the existing selection.

Selection Accessories

Hexagon software has several accessories which make selecting easy and
save time. It is important to remember their respective keyboard shortcuts to have
quick access during modeling, although their functions are accessible by icons in
the selection palette.

Loop

The loop tool lets you expand a selection along a surface by continuing it as
far as possible in the direction you started. In the case that a loop cannot be completed,
Hexagon automatically stops at the problem zone to keep a mistake from being made,
for example where several connected faces split into a Y intersection.

The loop tool works with faces and edges, but not with points.

When working in select faces mode, if only one face is selected the loop tool
selects one direction and shows the result. Clicking once again on the loop tool will
show the other possible selection. To determine a direction, you must have at least two
faces selected to specify the direction to expand the selection.

Usage:

Select an edge one or two faces to start.

Click on the loop icon in the selection palette.

Hexagon finishes the selection for you.

Keyboard shortcut: L

Ring

The ring tool lets you expand a selection along a surface by continuing it as
far as possible in the direction you started, as with the loop tool, but in parallel, like the
rungs on a ladder. In the case that a ring cannot be completed, Hexagon automatically
stops at the problem zone in order to not make a mistake, for example at the tip of a
triangle.

The ring tool works only on edges.

Usage:

Select an edge to start.

Click on the icon ring, in the selection palette.

Hexagon selects all the edges parallel to this edge.

Keyboard shortcut: K

Select Between

ThE Select between tool lets you connect a selection on a surface after defining
its start and finish. The tool only works on simple cases, like a direct path. Since
this tool is based on loop and ring, it will stop at the same types of problems which
would stop those other tools.

The select between tool works with faces and edges but not with points.

Usage:

Select edges or faces to mark the beginning and end.

Click on the icon select between, in the selection palette.

Hexagon adds to the selection all the edges or faces found between your indicated start and finish.

Note:

If the select between tool gives no result, it is because there was no result possible, such as the start and finish selection were not aligned on the surface (in the same loop/ring).

Keyboard shortcut: J

One Over N For Loop, Ring and Select Between

After extending the selection with the loop, ring and select between tools, it
is possible to set the selection step to select one over “N” elements in the loop.

This feature allows you, for example, to have one entity selected over 3 along
a loop, which will help you in doing specific operations, and avoid having to
do complex selection operations.

Usage:

In edge or face mode, do a loop, ring or select between selection.

In the tool property panel, set the value for the selection over “n” and the offset value.

In the 3D workspace, the updated selection appears.

Choosing another tool or clicking on the object or 3D workspace will make these options disappear.

Grow

The grow tool lets you expand the active selection, and works with faces, edges
and points.

Usage:

Make a selection

In the selection sub-palette, click in the + icon

In the selection menu, or in the contextual menu, then through the advanced selection sub-menu, choose “Grow”.

Shrink

The shrink tool lets you reduce the active selection, and works with faces, edges
and points.

Usage:

Make a selection

In the selection menu, or in the contextual menu, then through the advanced selection sub-menu, choose “Shrink”.

Hexagon subtracts from the selection all elements on the outer limits of the selection.

Boundary

The boundary tool lets you select the edges around a previously selected face.

Usage:

Make a selection of touching faces.

In the selection menu, or in the contextual menu, then through the advanced selection sub-menu, choose “Boundary”.

Convert

The convert tools let you change one type of selection into another. For example,
a selection of faces can be converted into a selection of edges or points. The
selection mode changes automatically depending on the conversion.

Usage:

Make a selection.

Use the appropriate “Convert” tool, located in the selection menu, or in the contextual menu, sub-menu advanced selection.

Hexagon converts automatically the selection

One Over N

The one over N tool lets you make a selection of alternate entities on an object, such
as one point out of two or one point out of three.

Usage:

Select your object and choose a selection mode.

In the selection menu, or in the contextual menu, then through the advanced selection sub-menu, choose “1/n”.

in the tool properties palette, input a value to divide by (more than 1).

Hexagon automatically makes the selection.

Validate the tool to keep the selection.

Invert

The invert tool lets you invert your selection on an object, and works with faces,
edges and points.

Usage:

Make a selection.

In the selection menu, or in the contextual menu, then through the advanced selection sub-menu, choose “Invert”.

Hexagon inverts the selection, or all the non-selected elements become selected and the original selection is deselected.

Unselect All

The unselect all command lets you cancel any current selection.

Usage:

In the selection menu, or in the contextual menu, then through the advanced selection sub-menu, choose “Unselect All”.

Hexagon automatically cancels the selection.

Selection Extensions

The selection is an important concept in Hexagon. It is used intensively,
and to maximize productivity some functions are accessible through specific
shortcuts and/or mouse manipulations. These functions will save time while modeling,
as well as will providing extra features which will allow you to perform advanced
selections with ease.

Extend Selection

This function allows you to extend an existing edge or faces selection along the
topology of the current object.

Usage:

Select edges or faces.

While holding both the Ctrl (Command on MacOS) and Shift keys, click-drag the mouse over the object: a blue line appears showing the direction of the extension. Change the direction of the extension by moving your cursor to a different area.

Example of use:

Once a “1 over N” Loop selection is performed, it is easy to make stripes of selections over the model.

Remark:

This tool being based on the topological structure of the objects, it may happen that some unexpected results occur, especially when the extension encounters a significant change in the topology, such as for example a Y intersection.

Shift Selection

This function allows you to move an edge or face selection over the object
topology.
Its use is similar to the extend selection tool previously described.

Usage:

Select edges or faces.

While holding the Ctrl-Key (Command-key on MacOS), click-drag the mouse over the object: a blue line appears showing the direction of the extension. Change the direction of the extension by moving your cursor to a different area.

Keyboard shortcut: Ctrl/Command+click while dragging the mouse.

Reset Selection

This is not really a tool. Rather, this action, triggered by a double-click, enables
the user to clear the active selection, according to the current selection mode, which
avoids in some cases having to click in an empty area of the 3D scene.

In some cases, when the user camera is very close to an object and when the
screen is covered by the geometry of the model, clearing the selection with a simple
double-click avoids the need to zoom out, click in the empty space, and zoom in again.

Usage:

With some edges, vertices, or faces selected, double-click on the current object to clear all selections.

Set Selection Auto Mode

This function is a quick way to activate the selection auto mode (Hyperlink)
when the current selection mode is set to vertex, edge or face, without having to click
on the corresponding icon in the selection panel.

Usage:

If the current selection mode is vertex, edge or face, and if there is an active selection, double-click on the current object or click outside to clear the selection.

Double-click on the object to activate the auto mode.

Remark:

If the current selection mode is vertex, edge or face, and if there is an active selection, you can set the auto mode back by doing two subsequent double-clicks.

Selection by Topology

This set of functions enables you to perform selection according to the topology
of the objects. They are useful to identify potential mesh structure issues (for example,
unseen triangles in a mesh which you want to be perfectly quadrangular), or to validate
a model before exporting it to another software product that does not support any kind of
topology (for example, software that does not handle faces with more than 4 points).

The following options are available under the “Selection” pull-down menu:

Select faces with more than 4 points.

Select triangles. Useful to detect triangles that could eventually cause troubles with smoothing, etc.

Select points sharing more or less than 4 edges: enables you to detect potential unwanted topology structures.

Usage:

Select the object you want to apply the specific selection on.

Call the appropriate selection command, either in the selections pull-down menu, or through the contextual menu, in the advanced selection section.

Hide/Show Selected Faces

It is often necessary to temporarily hide some faces of an object when working
on smaller or internal details. Three icons located in the control panel allow
you to hide the selected faces, to reveal hidden facets of the currently selected
object, or to reveal all hidden faces.

Objects having hidden faces have a small icon near their name in the scene
tree.

Usage:

To hide a list of faces: Select the group of faces to hide. Then click on the Hide selected faces icon from the control panel.

To reveal the hidden faces on an object: select the object and click on the Show. You can also click on the show hidden faces icon from the scene tree dialog near the object's name.

To reveal the hidden faces on all objects: click on the show hidden faces icon from hidden faces icon from the control panel.

Remarks:

Selecting entities on an object with hidden faces will not affect the hidden vertices, edges or faces. For example, a loop selection will only include the edges displayed on the screen, not the invisible ones.

Subsequently, all operations performed will not affect masked polygons. However, global operations such as moving, rotating, smoothing objects, will affect all polygons, even the masked ones.

Isolate Selection

When there are numerous objects in the scene, it is sometimes difficult to
navigate the scene or to work on a specific object. The “Isolate Selection” function
temporarily masks all the objects in the scene except the selected one, making a
more comfortable working environment.

Usage:

Select the object to isolate.

In the selection pull-down menu, choose “Isolate Selection”.

All unselected objects disappear from the scene.

To have the whole scene displayed again, just click again on “Isolate Selection” in the menu. The hidden objects will reappear immediately.

Remark:

“Isolate Selection” does not make the objects invisible like the “Mask” tool does. So using the “Unmask” tool will not make the objects hidden by the “Isolate Selection” function visible.